The large CP violation should exist to explain the matter universe. One of the strongest constraint of the search for the large CP-violation is the result of neutron electric dipole moment (nEDM). The present upper limit is |d_n|<3×10^{^-26} ecm (90% C.L.), which is very close to the predictions of new physics beyond the standard model of particle physics, for example, supersymmetry.

Now we are discussing another approach to search for large T-violation. The enhancement of the violation of time-reversal symmetry is predicted in the neutron capture reaction for some nuclei. We have already started the feasibility studies to search the T-violation in compound nuclei system at J-PARC. I will talk about our status of research and development for this experiment.